Diabetes among women with preterm births: outcomes of a Brazilian multicenter study.

Objective: The objective was to compare the maternal and perinatal characteristics and outcomes between women with and without diabetes in a Brazilian cohort of women with preterm births.

Methods: This was an ancillary analysis of the Brazilian Multicenter Study on Preterm Birth, which included 4,150 preterm births. This analysis divided preterm births into two groups according to the presence of diabetes; pregestational and gestational diabetes were clustered in the same Diabetes Group. Differences between both groups were assessed using χ 2 or Student's t tests.

Results: Preterm births of 133 and 4,017 women with and without diabetes, respectively, were included. The prevalence of diabetes was 3.2%. Pregnant women aged ≥35 years were more common in the Diabetes Group (31.6% versus 14.0% non-diabetic women, respectively). The rate of cesarean section among patients with diabetes was 68.2% versus 52.3% in non-diabetic cases), with a gestational age at birth between 34 and 36 weeks in 78.9% of the cases and 62.1% of the controls. Large-for-gestational-age babies were 7 times more common in the Diabetes Group.

Conclusion: Preterm birth among Brazilian women with diabetes was more than twice as prevalent; these women were older and had regular late preterm deliveries, usually by cesarean section. They also had a greater frequency of fetal morbidities, such as malformations and polyhydramnios, and a higher proportion of large-for-gestational-age and macrosomic neonates.